1. Field of the Invention
The present invention generally relates to swimming pool control systems. More specifically, the present invention is drawn to a system for preventing a swimming pool from accidentally emptying when the backwash valve is set in the backwash position.
2. Description of Related Art
Swimming pools provide exercise and entertainment for young and old alike. It is especially enjoyable when the swimming pool is in your backyard for use by family and friends. Unfortunately, swimming pools require some maintenance.
Part of the maintenance involves cleaning the pool filter. On many pools, a valve is employed to change the normal pool water circulation through the pump and direct the water from the pool through the filter in a reverse direction in order to wash the dirt and lint from the filter. This backwash water flows out of the system into a drain or the like. If the valve is not reset in a reasonable time (dependent on pool size, filter size, etc.) the pool will be drained to an extent requiring large amounts of expensive refill water. In extreme situations, the pool may be emptied completely and the pool pump damaged.
An inexpensive, easy to install system to prevent the above scenarios would certainly be a welcome addition to the art.
The related art is rife with complex systems for controlling water circulation in swimming pools and the like. Examples of such systems are disclosed in U.S. Pat. No. 4,310,144 (Nogaki), U.S. Pat. No. 4,482,461 (Hindman et al.), U.S. Pat. No. 4,505,643 (Millis et al.), U.S. Pat. No. 4,676,914 (Mills et al.), U.S. Pat. No. 5,584,992 (Sugimoto), U.S. Pat. No. 5,730,861 (Sterghos et al.) and U.S. Pat. No. 5,895,565 (Steininger et al.). As indicated above, all of the instant systems are complex and relatively costly to maintain. Further, none of the systems could be easily retrofitted or incorporated into the ordinary backyard pool without a great amount of expense.
U.S. Pat. No. 4,917,795 (Sable et al.) shows an automatic valve assembly used for pressure relief in swimming pool tanks. The valve does not function to control operation of the pool pump.
U.S. Pat. No. 4,869,817 (Mendoza et al.) is drawn to a valve lever control system for a swimming pool filter. The patentees do not contemplate provision of a timer to control pump operation.
U.S. Pat. No. 3,963,375 (Curtis) discloses a shut-down circuit for a re-circulation pump. The circuit is responsive to the discharge pressure of the pump.
U.S. Pat. No. 3,365,064 (Horan, Jr.) discloses a swimming pool backwash assembly but makes no provision to control the timing cycle of the backwash process.
None of the above inventions and patents, taken either singly or in combination, is seen to disclose a timer system associated with a backwash valve as will subsequently be described and claimed in instant invention.